This experiment tested a treatment designed to improve choral students' expressiveness regarding keyword emphasis and phrase shaping. The treatment was founded upon the constructivist belief that students actively construct conceptual knowledge through problem solving. Participants were 46 university students randomly selected from a nonauditioned choir. A time-series design and backward-elimination ANOVA was used to produce and analyze the data. A treatment effect was found for both keyword emphasis and phrase shaping. Implications suggest that choral educators may increase students' ability and propensity to independently interpret music in terms of keyword emphasis and phrase shaping by providing problem-solving opportunities to students. (Contains 3 tables.)